working with more than one spread sheet

I'm trying to use XL to build a diary for a small tourist business. I would like to have a page for each client in which I add things to do each day. I would like to use the front page as a summary of the latest task written up for each client. I would like to use one particular cell for writing in updates and move the rest down. I have defined cells on the first page to correspond with the cell on each client page in which I write the updates. Only as I move them down to make way for a new update the corresponding cell on the first page continues to refer to the info that was on that cell. How do I make the front page cell refer to a constant cell on other pages? I hope my question is clear and I would qppreciate any help.

INDIRECT would probably work. For example,

=INDIRECT("Sheet1!A3")

will always look to Sheet 1, cell A3.